The present invention relates to distributors for tobacco, especially to distributors which are used in cigarette making machines to form a relatively wide silver or fleece consisting of tobacco shreds and ready for conversion into a narrow tobacco stream which is suitable for trimming or immediate wrapping into cigarette paper.
A tobacco distributor in a cigarette making machine comprises a magazine for a supply of tobacco shreds, a carded drum which withdraws a layer of tobacco particles from the magazine, and additional components which equalize the layer and segregate heavier particles, such as fragments of ribs, birds' eyes, pieces of metal, sand, rock and the like. The additional components include picker rollers, refuser rollers, winnowers, brushes and other moving parts.
Problems arise in conventional distributors because the supply of tobacco is the magazine of a distributor contains shorter and longer tobacco shreds. As a rule, the carding of the aforementioned drum is more likely to withdraw longer shreds so that the shorter shreds tend to accumulate in the magazine and are removed sporadically in the form of relatively large coherent clumps. The shorter shreds continue to adhere to each other during further processing in the distributor and are likely to form, by themselves, certain portions of the fleece and thereupon of the narrow tobacco stream. This is undesirable because accumulations of shorter shreds affect the quality of cigarettes, especially because shorter shreds are more likely to escape at the ends of wrappers so that the heads of cigarettes containing relatively large quantities of short shreds are too soft. The formation of relatively short shreds cannot be avoided; such shreds invariably constitute a certain percentage of tobacco in the magazine of a distributor. It has been found that the carding of a conventional drum which is used to withdraw a continuous layer of tobacco shreds from the magazine acts not unlike a classifying device which segregates longer shreds from shorter shreds and removes the thus obtained accumulations of shorter shreds at irregular intervals.